gistfile1.m

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
    
    if ([annotation isKindOfClass:[PinLocation class]]) {
        
        //MKAnnotationView *annotationView = (MKAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
        static NSString *identifier = @"PinLocation";
        MKPinAnnotationView *annotationView = (MKPinAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
        if (annotationView == nil) {
            annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
            annotationView.enabled = YES;
            annotationView.canShowCallout = YES;
            annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeInfoLight];
            //annotationView.animatesDrop = YES;
            
        } else {
            annotationView.annotation = annotation;
        }
        
        return annotationView;
    }
    else if ([annotation isKindOfClass:[ImagePin class]]){
        static NSString *identifierImage = @"ImagePinLocation";
            MKAnnotationView *annotationImageView = (MKAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifierImage];
        if(annotationImageView){
            return annotationImageView;
        }
        else {
            annotationImageView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifierImage];
            annotationImageView.canShowCallout = YES;
            
            annotationImageView.image = [UIImage imageNamed:@"image_bg_mappa"];
            
            UIImage *frame = [UIImage imageNamed:@"image_bg_mappa"];
            ImagePin *imagePinImage = annotation;
            NSLog(@"%@", [NSString stringWithFormat:@"%@", imagePinImage.image]);
            
            
            NSString *urlStringForImage = [NSString stringWithFormat:@"%@", imagePinImage.image];
            NSURL *urlForImage = [NSURL URLWithString:urlStringForImage];
            UIImageView *imageView = [[UIImageView alloc] init];
            
            [imageView setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@", urlForImage]] placeholderImage:[UIImage imageNamed:@"avatar-placeholder.png"]];
            
            UIGraphicsBeginImageContext(CGSizeMake(annotationImageView.image.size.width, annotationImageView.image.size.height));
            
            [frame drawInRect:CGRectMake(0, 0, frame.size.width, frame.size.height)];
            [imageView.image drawInRect:CGRectMake(2, 2, 48, 38)]; // the frame your inner image
            
            annotationImageView.image = UIGraphicsGetImageFromCurrentImageContext();
            
            UIGraphicsEndImageContext();
            
            UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
            [rightButton setTitle:@"" forState:UIControlStateNormal];
            annotationImageView.canShowCallout = YES;
            annotationImageView.rightCalloutAccessoryView = rightButton;
            annotationImageView.enabled = YES;
            annotationImageView.userInteractionEnabled = YES;
        return annotationImageView;
        }
    }
    else {
        return nil;
    }
}

how to show custom pin instead user picture ?